Resistance device and unit therefor



Nov. 19, 1935. D. F. YHASTINGS 2,021,509

RESISTANCE DEVICE AND'UNIT TBEREFOR Filed Jan. 9, 1934 miiiMWNNWWMWNW Y5g INVENTOR Joya/i ftgas r gs ATTORNEY resistance device and While I amaware LNL ,JUU

UNITED STATES ATENT OFFICE spruce f nssrs'rsncsnnvrcs AND nm'r macroDonald F.

nastinsa Fairla 1., illigllor to Hardwick, Kindle, Inc.,- Newark, N. J.Application January 9, m4, Serial No. 195,869 [Claims- 7 (Cl. 20 1-63)This invention relates to an improved form of unit therefor. thatresistance units and devices have been made in mamr ways, yet I be- 5lieve the structure shown and described herein includes a number ofadvantages not present in prior art devices with-which I of the objectsof duce a compactwire-wound resistance unit of It is one am familiar.

my invention to prorelatively high resistance value.

Another object of my invention is to produce a compact wire-woundresistance unit which will dissipate a relatively large amount Anotherobject of my of power. invention is to provide a resistance unit whichcan be easily and cheaply made, yet one that is rugged in constructionand will therefore stand much abuse in operation.

a new type of resistanc in handling and invention is to provide sembledin groups to make up a resistance de ice which willtake up a yet whichminimum -amount of space, will have a high wattage rating due to thelarge radiating surface with respect to volume attained by myconstruction.

These and other objects will be apparent to one skilled in the art ofconstructing resistances,

after reading the Figure 1 is a plan units without the outerspecification tion with the annexed drawing,

view of one of my resistance taken in conneccovering applied thereto.

Figure 2 is a longitudinal section on the line 2-2 of Figure 1, but withposition. Figure Figures 1 and 2. Figure=4 isa the outer covering indevice composed pianview of a modified form of plate which maybe. usedas aterminal and binding plate. 1 Figure 5 is ure 4.

a section lizure 6 is a plan view winding which may be tionof thecomplete unit diagrammatic illustration show- Figure '7 15'8- on theline of Figof one form of resistance utilized in the construcing themanner'in which the resistance winding I of Figure 6 may be assembledbetween the binding and terminal plates Figure 8 is a view somewhatsimilar to Figure 5,

showing a different way of making. contact with such plates will act totribute the'heat over plate-of the resistance unit. and 10 show modlfledforms cf terminal and binding plates.

1' and ;quickly collect and disthe-surface of the unit,

' dissipated. Between the units as shown in as above described;1they'-m.to the terminal plates and hen next adjacent unit, andthe preferably oflnsulatingmat 2 are flat metallic" plates preferably of soft copper, forthe reason very good conductor of heat andthe nee? whereby the heat fromthe winding is rapidly I plates 1 and 2 there is located a resistancewinding 3 wound on a flat form 4 of heat-resisting material such as asheet 'of mica. The plate I is prevented from contacting with the turnsof the winding 3 by an insulator 5, and likewise, the turns of thewinding 3 are prevented '2 by an insulator preferably of goodheat-resisting material such fromeontacting with the plate 6. Theinsulators 5 and 6 are as mica.

,To hold the plates l and 2 in position over the insulators 5 and 6. andthe resistance winding 3, the plate 2 is provided withiingers 1andilwhich are bent upwardly and lie on the-* insulator 5, leaving aspace ii which is provided by'notching out the corners of the plate I."Likewise, fingers 9 and Iii are positioned on the bottom side of theunit in a similar manner. The plate [is provided with a terminalextension Hand the plate 2, with a terminal extension IS. The extensionsi2 and It may be each provided with an eyelet, it which also serves toclamp the ends I of'the winding, one end 55 being shown, as eachvitreousenamel, with the ei'tception of the iaised portion 16 and thatportion of the terminals I2 35 and it around the eyelets ll The enamelbridges over the spaces I l and completely seals the whole unit, thusrenderingthe same] substantially moisture-proof. A'ftcrf tli'mnits ar ecompleted aybeassembl'ed in any 40 use f-of the eyelets It formoking'connections otheTextremi-ty satisfactory manner. by. which mayalso be used of the resistance winding. In addition, the units"iri'ay'be assembled as 5 shown in glgure 3 by stacking a plurality of units ina substantlallymeehanical, parallel relationship, whereby the rais f isin contact with the ra" in assembled relationin any satisfactory manheras by a mounting t mpo t. i upright supports It and I l-oneof which,such as ll. carries a-clamping'j' rew'jfl forfclaniping 55 positionandfor making electricai connection throughthe the post-2i to the'bindin gpost :2. By reference-to that fiit fi iay be d .50.

.co c nsuptotheenamelingofflieunits '-In'some,cases,rmay1uethesidefingers".

2 a a,o21,goe

resistance and any one of the units maybe used independent of the othersby connecting the terminal wires directlyto the terminals l2 and I 3 ofthe unit desired, instead of to the binding 5 posts 2! and 22; or oneside of the circuit may be connected to both the binding posts 2| and 22and the other circuit wire connected to any one of the terminals l2 andII of the different units, thereby giving a series parallel arrangementof the resistance units. In addition, one side of the circuit may beconnected to either one of the terminals 2| or 22, while the other sideof the circuit may 'be connected to any one of the 1 terminals 01' thevarious units, thereby providing what is generally referred to as atapped resistor. I

In Figure ,4, I have shown a terminal and binding plate I with thebinding lugs 9 and II and raised portion l6 as in Figure 1, but theterminal I2 may be provided with an integrally formed eyelet 23 aroundwhich one terminal end of the resistance-wire 24 may be wound, and thenthe eyelet 23 is spun over or forced into position to clamp the wire 24.While I have shown an in- 25 tegral eyelet 23,- it is to be understoodthat a separate eyelet may be used at this point if desired. Thisconstruction leaves a hole 2| in the terminal l2 for ease in soldering-aconnecting wire thereto, or for mounting purposes, in which case theterminal wire may be wound around the terminal 2 at the V-shapedJunction point 2!.

Instead of a single form 4 carrying the resistance winding 2, I may usea plurality of 3 windings 3 all wound on a unitary form 21 which hasslots 28 punched therein before the winding 3 is applied thereto asshown in Figured.

By constructing .theforin 21 in the manner just described, the form maybe readily folded uponthelineoftheslotsflasahowninl'igure 7, without anydanger 'of breaking the winding at these bendable points, insulators asbeing utilised between the various windings I of the unit structure.After the form has been folded up as shown in Figure 7, the extremitiesof the winding are connected to the plates l and. 2 which are appliedand fastened in position as has been described.

clamped over the stack andinto thespsees s2providedontheplatelasshowninligurelit so being understood that thefingers II and the spacesornotchesflaresuchthattheflmersflwillnot'touchanyportionoftheplate 2, This construction tends topreventany weaving ofth'e plates I and '2 during the which are indicatedby dotted line in connec "tion with the plate I, v

adapted to be positioned inclearance notches I4 7 indicated by dottedlines in l'isure' ll.

From what has been said, it will be understood that the type ofresistance unit herein shown and described, will radiate a considerableamount of heat; that is to say, the wattage rating of the '75 unitisrelatively high. .This feature is especially useful when the units arearranged in a com.

- pact space as illustrated in Figure 3. Furthermore, the constructionof the unit is such that if one should burn out in an arrangement suchas shown in Figure 3, this unit may bereadily 6 and quickly replaced bya new unit.

While I have shown a series of sections wound on a single bendable form21, as in Figure 6, it is to be understood that a number of individualsections as shown in Figures 1 and 2 may be 10 stacked between thebinding plates I and z, and

plates positioned on and overlying the faces of 20 the opposite sides ofthe unit against said lastmentloned insulators, said plates beingprovided with means for locking themselves in position over saidinsulators, and means on each plate for connecting an end of the windingsecurely. there- 25 to, said unit having an outer covering of bakedvitreous enamel.

2. A resistance unit as set forth in claim 1, characterized in that thecentral part of eachof said plates has a raised uncovered portion forthe purposes described. I

3. A resistance device consisting of a relatively flat stack or elementsincluding a pair of metal-, lic binding plates having portions bent overthe stack to form a self-lock and also having termi-- nal projections, aresistance winding positioned between but insulated from said plates,,said winding being wound on' a single elongated flat form ofheat-resisting material having connected but foldable sections, thatpart of the winding on so one section being I parsted by a suitableinsulater from the next adjacent section winding when the sections arefolded up for placement between ssid metallic plates. and an outercovering of baked vitreous enamel over the whole device 4 except atleast the ends of the terminal probe- 4. A including amounting havingcircuit terminals, said mounting-carrying a plurality ofresistaneeunits, each unit inciudl0.ingafiatstachofeiementsandapairofmetaliic bindiu plates havingself-locking portions ex- ;tending over opposite sides of the stack andalso having terminal projections, and at least one resistancewoundonafiatformtolie" between but insulated mm mo plates. the ends ofthe winding-being connected betweensaid plates, ch plate having anmull'llflat raised connscfsd'in series. and eachunlt being covered 7with a baked vitreous heat-resisting material expt for said raisedportions and the endsof said terminals 5. A resistance device includinga plurality of. resistance units as defined in claim 4 in which theunits are arranged in mechanical parallel relationship with thecentraluncovered portions in contact, means being provided for holding saidunits in said position whereby the units may be readily connected inseries or series parallel relationship, or any one of the units may beused separately, or the units may be used. or connected as a tappedresistor.

DONALD I". HASTINGS. 76

